#include <bits/stdc++.h>
using namespace std;
 
const int ZERO = 1000;
const int MAX = ZERO + 1 + ZERO;
 
bool CS[MAX][MAX];
vector<pair<int, int>> P;
 
int main()
{
    int n;
    cin >> n;
    while (n--) {
        int x, y;
        cin >> x >> y;
        x += ZERO;
        y += ZERO;
        CS[y][x] = true;
        P.emplace_back(x, y);
    }
    sort(P.begin(), P.end());
    int a = 0;
    for (int i = 0; i < (int)P.size(); ++i) {
        for (int j = i + 1; j < (int)P.size() && P[i].first == P[j].first; ++j) {
            int s = P[j].second - P[i].second;
            int x = P[i].first + s;
            if (x >= MAX) {
                break;
            }
            int y1 = P[i].second;
            int y2 = P[j].second;
            if (CS[y1][x] && CS[y2][x]) {
                ++a;
            }
        }
    }
    cout << a << endl;
    return 0;
}

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10
0 1
0 2
0 5
3 0
3 2
3 5
4 1
4 5
5 0
5 2